Shoe sole

ABSTRACT

A shoe sole which, in the heel and ball regions, comprises deformable cavities which are connected to one another and to the surrounding air by means of lines which can be closed by valves. Provided in the bending region of the sole is a transverse gap which is closed at the bottom and is filled by a further deformable and partially closable cavity which comprises at least one outlet line to the surrounding air and is connected to the cavity in the ball region via a line which can be closed by a valve. When stress is applied to the heel region, the line connecting the cavity in the region to the surrounding air is closed by the valve, the line leading to the cavity in the ball region is opened, the line leading to the cavity in the gap is closed, and the outlet lines in this cavity are open. When the sole is aligned straight as desired by opening the gap, the lines are closed again and the outer line is opened in order to re-establish the state in which the heel region can be stressed again.

The present invention relates to a shoe sole, in the heel region and inthe ball-of-the-foot region of which there are air-filled cavities ineach case which are connected to one another via a line and valves whichdamp the impact when the foot is placed on the ground and, in thebending region, have a further cavity, which aids the forward movement.

It is known to provide shoes with elastic foam soles which damp theimpact when the foot is placed on the ground. The deformation of thesole which takes place as a result of the foot being placed on theground, however, requires additional force to be exerted during walking.

It is also known to provide, in the heel region and ball-of-the-footregion of the shoe sole, deformable, air-filled cavities which areconnected to one another by lines, in order that, in addition to dampingthe impact when the foot is placed on the ground, there is also animprovement in the natural rolling movement of the foot. In this case,the air, possibly under elevated pressure, is forced, via the line,directly out of the region which is subjected to loading into the regionwhich is not, this being intended to massage the muscles of the foot asa result. The compression energy is not utilized for forward movement(see German Patent 116 106 and DE-B 11 95 639).

German Patent 30 12 945 describes a shoe sole in which the energy usedwhen the heel is placed on the ground is to be reused in the last phaseof the step when the foot leaves the ground. For this purpose, it isprovided that the compressed air which, when the heel is placed on theground, is produced in the first cavity, which is located in this regionof the sole, is collected in an intermediate store, from which it is tobe directed, via a valve which is initiated by the bending of the shoesole, into the second cavity, which is located in the ball-of-the-footregion of the sole, in order to inflate said second cavity at the pointin time when the foot is lifted off the ground and thus to aid thelifting movement. Since in this position, however, the air in thiscavity has already been compressed by the loading of the ball of thefoot, on which the entire body weight rests at this point in time, airdoes not, in practice, flow out of the intermediate store, which is notat a higher pressure.

DE-A 33 13 767 discloses a further insole which is to effect impactdamping and heat compensation during walking. In the case of thisdevice, cavities in the ball-of-the-foot region and heel region are ineach case connected to the outside air via valves and to one another viaa line and a valve. When the sole region is subjected to loading, airflows, via said line and the valve, into the heel region, from where,when the heel region is subjected to loading, it is discharged to theoutside air via the valve. While the heel region is subjected to loadingand the sole region is relieved of loading, outside air issimultaneously taken in via the valve located in the sole region. Theimpact damping is regulated by corresponding dimensioning of thethrough-valves. The impact energy is not utilized here for forwardmovement either.

DE-B 39 42 777 discloses a further device in which a cavity in the heelregion serves for impact damping, the compressed air being routed vialines into the sole region, where it flows out and displaces the humidair collected in the shoe interior. When the heel region is relieved ofloading, fresh outside air is taken in from the outside viacorresponding valves. It is also the case here that the energy used whenthe foot is placed on the ground is not utilized for forward movement.

The object of the present invention has thus been to find a device whichmakes it possible for the forces which are exerted when the foot isplaced on the ground to be utilized for aiding the walking action.

This object is achieved by the features of the main claim and by thoseof the subclaims.

The device according to the invention achieves the situation where onthe one hand, in a manner known per se, the impact when the foot, inparticular the heel, is placed on the ground is cushioned by air-sealedcavities and, in a novel manner, the energy stored by the compression ofthe air is utilized in order to force the sole to straighten out,shortly before the foot is lifted off the ground, and thus to impart aforwardly directed impulse to the shoe. In a preferred embodiment, thecompressed air is additionally utilized for cooling and drying the shoeinterior.

The invention is explained in more detail hereinbelow with reference tothe drawings, in which:

FIG. 1 shows the perspective view of a shoe sole according to theinvention;

FIG. 2 shows the longitudinal section of a shoe with the shoe soleaccording to the invention in the non-loaded state;

FIG. 3 shows the shoe sole at the point in time when the heel is placedon the ground;

FIG. 4 shows the shoe sole during the rolling operation as the heel isrelieved of loading;

FIG. 5 shows the sole at the stage when the ball of the foot issubjected to loading;

FIG. 6 shows the sole shortly before the foot is lifted off the ground;

FIGS. 7a-7d show a mechanism for producing a connection to the outsideair, the mechanism being shown at various actuating stages; and

FIG. 8 shows the schematic illustration of an initiating mechanism.

FIG. 1 shows a shoe with the sole 1 according to the invention, a firstcavity in the heel region 2, an intermediate pressure-storage space(second cavity 3) in the ball-of-the-foot region, and a further, thirdcavity 4 in a gap 5 of the sole 1, said gap being located between theball-of-the-foot region and heel region. A line 6 with a valve 7connects the cavities 2 and 3, and a line 8 with a valve 9 connects thecavities 3 and 4. Line 10 and blocking mechanism 17 connect the thirdcavity 4 to the outside air and/or the shoe interior. A line 11 and avalve 12 connect the first cavity 2 to the outside air. An outsole 13 isprovided beneath the sole 1. The initiating mechanism 19 comprising[sic] the valve 9, with its valve housing, the valve spring and thevalve pin, as well as the pressure-initiating screw 14. As the sole isbent, the screw 14 in the channel 15 advances toward the valve 9, whichis located opposite on the other side of the gap, until pressureinitiation takes place. The intermediate pressure-storage space (secondcavity 3) advantageously has a configuration 16 which is based on thebearing region of the ball of the foot. The blocking mechanism 17,formed by drawn-in walls, closes off the third cavity 4 in a more orless sealed manner depending on expansion, it being possible for the airto escape, if appropriate, via outlet opening 18 with discharge line 10.

The walls of the various cavities preferably consist of an elasticrubber or plastic.

It is only in exceptional cases, for example when the sole materialitself has sufficient strength or gas-tightness, that the walls of thevarious cavities may be produced from the sole material itself.

Instead of the blocking mechanism 17, it is also possible to provide, inthe line 10, a valve which opens when the gap 5 is completely open andcloses again as the gap is bent together. It is also possible that thefirst cavity 2 may optionally be connected to a portable, controllable,positive-pressure oxygen chamber by a valve with a bearing-pressureinitiating mechanism including an outwardly leading line.

The valves used are preferably straightforward non-return valves or flapvalves which are controlled by the pressure or negative pressure in therespective line. It is only for the valve 9 that it is necessary toprovide for control by an initiating mechanism coupled to the bendingaction of the sole.

FIG. 2 shows a shoe with the sole in a state in which none of thecavities is subjected to loading.

FIG. 3 shows a view of the sole at a point in time when merely the heelregion is subjected to loading, with the result that the first cavity 2is compressed (illustrated by the top wall bulging inward) and air flowsvia the valve 7, which has been opened by the compression, into thesecond cavity 3 (illustrated by the top wall bulging outward); at thisstage, the valves 12 and 9 are closed. The blocking mechanism 17 is openin this position, with the result that the third cavity 4 is relieved ofpressure.

FIG. 4 illustrates the point in time at which the heel is lifted off theground and the body weight is shifted into the ball-of-the-foot region.The discharge of most of the air volume from the third cavity 4 hasalready been carried out at this stage; the blocking mechanism 17 hasbeen closed by the bending of the sole 1 and the compression of thethird cavity 4. The bending movement of the sole, which is associatedwith the weight being shifted, does not require any additionaldeformation energy. In this state, the valves 9 and 7 are closed. Byvirtue of the intermediate pressure-storage space 3 being placed beneaththe ball of the foot, the pressure in said second cavity 3 can beincreased a second time. Valve 12 is open in this phase, with the resultthat air can flow into the first cavity 2 from the outside and replacesthe air which has previously been discharged into the second cavity 3.By virtue of the predetermined elastic stressing of the walls of thefirst cavity 2, the release of pressure from the heel region produces avacuum into which the air overline 11 [sic] flows.

FIG. 5 shows the second compression of the already pre-compressed air bypressure of the ball of the foot on the second cavity 3 (illustrated bythe top wall and the side walls bulging outward). This space 3 isadapted anatomically in accordance with the main bearing-pressure pointsat the level of the center of the ball of the foot and of the ball ofthe big toe as well as the toes. At this stage, the air which has beencompressed twice in this way4 [sic] has just begun, by further bendingof the sole 1, to flow further opening valve 9 [sic].

FIG. 6 shows the point in time when the sole is lifted off the ground.Valve 9 is open in this position, with the result that thetwice-compressed air in the second cavity 3 widens the third cavity 4and thus forces the gap 5 apart and straightens out the sole 1 again.Valve 7 is closed in this position. As the sole 1 straightens out moreand more, the bending-induced initiating pressure on the valve 9decreases, with the result that it is closed again once the sole hasbeen straightened out.

The dimensions of the cavities 2 and 3 are to be selected such that thecompressed air produced therein corresponds approximately to the fillingvolume of the cavity 3. Relatively small deviations are compensated forby the change in the operating pressure in the cavities 3 and 4.

FIG. 7a shows a perspective illustration of the third cavity 4. In orderto achieve extended throughflow as expansion increases, it is expedientfirst of all to place the outlet 18 of the discharge line 10 to thegreatest possible extent opposite the inlet of line 8. It is alsoexpedient for the outlet opening 18 to be narrower than the inlet ofline 8. The blocking mechanism 17 is indicated by three parallel wallswhich, when relieved of loading, release an opening.

FIG. 7b shows the third cavity 4 in cross section. The cavity is in acompressed state. At this stage, air cannot escape through the wall-likeinwardly directed projections of the blocking mechanism 17, saidprojections interengaging as a result of the compressed state of thecavity 4; in contrast, compressed air flows in from the second cavity 3via the line 8.

FIG. 7c shows the third cavity 4 in a somewhat widened state, once someof the compressed air has been introduced through line 8. The stepinvolving the expansion, and thus widening of the gap, which the thirdcavity 4 is undergoing is more or less complete at this stage.

FIG. 7d shows the third cavity 4 in the fully widened state. The wallsof the blocking mechanism 17 are open. A large proportion of the airvolume located therein, i.e. the positive pressure fed from the secondcavity 3, can escape at this stage, until bending of the sole takesplace, without a lot of deformation energy being required.

FIG. 8 shows a schematic illustration of an initiating mechanism 19 forthe valve 9 in a movement phase in which initiation has not yet takenplace. By virtue of this initiating mechnism 19, it is only in the stateof pronounced bending of the sole 1, in the closed state of the gap 5according to FIG. 5, that the valve 9 is opened and in the state inwhich the gap has been relieved of pressure, according to FIG. 3, thevalve 9 is closed again in order thus to reproduce the initial stateaccording to FIG. 2. The adjusting screw 14 in channel 15, which screwpresses on the initiator (valve pin) of the valve 9, and allows air tobe let into line 8, during bending of the sole, can set precisely thepoint in time at which opening takes place.

Alternatively, the valve 9 may also be controlled via an initiatingmechanism which reacts to the pressure with which the sole bears on theground in the ball-of-the-foot region.

A further advantage of the device according to the invention consists inthat the air emerging from the chamber 4 need not be discharged into thesurroundings in an unutilized state; rather, said air can be directedinto the interior of the shoe via a corresponding line 10, with theresult that it displaces the sweat-containing air from there and ensuresdrying and cooling of the foot. A corresponding principle is indicatedby the illustration of the line 10 in FIG. 1.

In order to ensure optimum widening of the gap 5, the third cavity 4 hasto have its main application surface at the top edge of the gap 5, inorder that the greatest possible lever can be utilized. It is preferablefor an oval design of the cavity 4 to be selected, but alternatively,for stability reasons, it is also possible for a tube-like orwedge-shaped design having the greatest extent in the top region to beadvantageous. The walls of the gap 5 itself should consist of relativelystrong material, in order to convert the amount of pressure applied bythe cavity 4 into the bending-back action of the sole in a loss-freemanner as far as possible, for which purpose it may also be favorablefor those regions of the sole which are adjacent to the gap likewise tobe formed from relatively strong material. Since the foot subjects thesole to barely any loading, if any at all, at this location, thecorresponding stronger formation of the sole material at this locationis of no importance as far as walking comfort is concerned. In order todesign the gap itself to be stronger, the gap termination, about whichthe two sole parts move during the corresponding bending movement andwhich ends about halfway through the thickness of the sole, must ofcourse consist of a flexible material, for which purpose, for the sakeof simplicity, an additional sole 13 made of a flexible material isadhesively bonded on the strong sole 1 according to the invention, thusforming a type of "hinge".

In a variant which is more straightforward to produce, the sole 1 isprovided with its initiator in the manner according to the invention,but valve 9 is dispensed with. In this case, the line 8 has to be ofsuch a length that the air running through the cavities withoutobstruction requires such a period of time to reach the third cavity 4from the second cavity 3 that the air only enters into the third cavity4 once said cavity has already been bent and/or the discharge of airtherefrom has been completed.

In a more complex variant, the output can be increased by the additionalintroduction of a positive pressure from an external source. In thecourse of natural movement, this artificial positive pressure, alongwith the other positive pressures produced by the walker, results in avastly improved pressure/movement output.

The device according to the invention ideally makes it possible, on theone hand, to damp the energy used when the foot is placed on the groundduring a walking or running movement, and thus to relieve the walker'sleg and hip joints of loading, and, on the other hand, to aid thewalking movement itself in an active manner, in the [sic] at least someof the stored and enhanced energy used when the foot is placed on theground is discharged at an anatomically expedient location of action inconjunction with additional ventilation of the shoe. The forward angularmomentum which is produced by the front part of the sole being raised asthe sole 1 is forced to straighten out is intended to give the walkerthe slight feeling that the shoe is actively aiding him/her; inparticular the forward angular momentum can also assist the following-onaction of the leg.

LIST OF DESIGNATIONS

1 Sole

2 First cavity in the heel region

3 Second cavity in the ball-of-the-foot region/intermediatepressure-storage space

4 Third cavity in the bending region

5 Gap

6 Line

7 Valve

8 Line

9 Valve

10 Line/discharge line

11 Line

12 Valve

13 Outsole

14 Adjusting screw

15 Channel

16 Configuration of cavity 3

17 Blocking mechanism

18 Outlet opening

19 Initiating mechanism

What is claimed is:
 1. Shoe sole which, in the heel region, has a firstcavity and, in the ball-of-the-foot region has a deformable secondcavity, the two cavities being connected to one another and the outsideair via lines, said lines being in communication with valves that areoperable between an open position and a closed position wherein,a)provided in a bending region of the sole is a transversely running,downwardly closed gap, which includes therein a deformable third cavity,the third cavity being connected to the second cavity via a first linewhich is in communication with a first valve that is operable between anopen position and a closed position and has at least one discharge lineto outside air, said discharge line in communication with a blockingmechanism that is operable between an open position and a closedposition; b) the second cavity is separated off by valves and acts as anintermediate pressure-storage space; c) provided that, when the heelregion is subjected to loading, a second line connecting the firstcavity to the outside air is closed by a second valve, a third lineconnecting the first cavity is open, the first line connecting the thirdcavity, is closed and the discharge line from the third cavity is open;d) further provided that, when the heel region is relieved of loadingand the ball of the foot is subjected to loading, the second line fromthe first cavity to the outside air is open and the third line to thesecond cavity is closed, and, as a result of simultaneous bending of thesole, the gap and the third cavity are compressed and the first line tothe second cavity and the discharge line from the third cavity areclosed by a blocking mechanism; e) once the sole has been bent and thegap has been closed, an initiating mechanism opens the first line fromthe second cavity to the third cavity and closes the discharge line atthe third cavity to the outside air, the third line from the firstcavity to the second cavity being closed and the second line to theoutside air being open; f) when the sole is straightened out and the gapis again opened, the first line and the second line are closed and thedischarge line of the third cavity is opened by the blocking mechanismto reproduce the state for the loading of the heel region according toc).
 2. A shoe sole according to claim 1, wherein the valves arenon-return valves.
 3. A shoe sole according to claim 1, wherein theinitiating mechanism is set in the first line.
 4. A shoe sole accordingto claim 3, wherein the initiating mechanism includes a time delay.
 5. Ashoe sole according to claim 1, wherein, in the top region of the gap,the third cavity is wedge-shaped, round or oval shaped.
 6. A shoe soleaccording to claim 1, wherein the discharge line of the third cavity, inthe gap, leads into the interior of the shoe.
 7. A shoe sole accordingto claim 1, wherein the walls of the gap and the adjacent regions of thesole are formed from a non-flexible material.
 8. A shoe sole accordingto claim 7, wherein a flexible outsole is provided beneath the sole. 9.A shoe sole according to claim 1, wherein the second cavity isanatomically adapted in accordance with the centers of gravity of thebearing pressure of the ball of the foot.
 10. A shoe sole according toclaim 1, wherein the first cavity is connected to a portable,controllable positive-pressure oxygen chamber by a valve with abearing-pressure initiating mechanism including an outwardly leadingline.
 11. A shoe sole according to claim 5, wherein the third cavityincludes a blocking mechanism which comprises mutually opposite,wall-like inwardly directed projections which, depending on thecompression or expansion of the cavity, interengage to a more or lesspronounced extent.
 12. A shoe sole according to claim 3, wherein theinitiating mechanism includes an adjusting screw that acts on the firstvalve, said adjusting screw being provided in a channel locatedlaterally on the outer border region of the sole, parallel to thelongitudinal axis.
 13. A shoe sole according to claim 1, furthercomprising that the first valve and the initiating mechanism arereplaced in the gap by an extended line of such a length that bending ofthe sole is achieved at a point in time before the unobstructedthroughflow of air through this line into the third cavity.
 14. A shoesole according to claim 7, wherein a flexible outsole is providedbeneath the sole and holds the sole gap together.
 15. A shoe soleaccording to claim 3, wherein the initiating mechanism includes anadjusting screw that acts on the first valve, said adjusting screw beingprovided in a channel located laterally on the outer border region ofthe sole, and oblique to the longitudinal axis.